1. Technical Field
The present invention relates to an optical waveguide and a method for manufacturing the same.
2. Related Art
Recently, in a small-size instrument as represented by a cellular phone, a structure in which plural substrates are connected together by a hinge mechanism or a slide mechanism has been used commonly used in order to, for example, separate a display section and an operating section from each other, which may improve handling properties and portability. Further, improvements in performance of small-sized instruments necessitate high-speed, two-way transmission of vast amounts of digital data generated by attached imaging elements or the like, required data for a display section that allows high-definite display, and the like, to another substrate. For this reason, two-way data transmission technology using a polymeric optical waveguide that is disposed so as to pass through a hinge mechanism section or a slide mechanism section has been demanded.
Accordingly, in the polymeric optical waveguide used in the small-sized instrument, high flexibility adapted to the hinge mechanism or the slide mechanism is required. For example, assuming that the space between cell phone substrates connected by a slide mechanism is indicated by D, it is at least required that D be not more than 4 mm. Due to advancement of thin-model cell phones, it has been recently required that D be reduced to about 2 mm. The polymeric optical waveguide used therein is required to have only a small insertion loss and a small variation in the loss even when it is in a bending state corresponding to the above D value, and is repeatedly bent and unbent on the assumption of long-term use.